F. Hou, I. Mardon, Z. Yang, C. Goode
Cirrus Materials Science Ltd.,
New Zealand
Keywords: superhydrophobic, hydrophobic, hydrophilicity, hardness, coefficient of friction corrosion resistance, wear resistance, coatings, sustainable, low energy, medical, PEO
Summary:
Cirrus technology offers a low-voltage, non-toxic PEO super hydrophilic coating technology for application to light alloys. The novel surface finishing technology provides thin, adherent, and durable protection for alloys at low cost with an exceptionally low energy and environmentally sustainable process. The process has applications for magnesium, aluminium and titanium substrates or films. The requirements of enhanced energy efficiency, emission reduction and improved performance necessitates the development of lighter automotive and aerospace components with enhanced functional characteristics such as superhydrophilicity. Light metals are essential to reducing weight; however, most light alloys require protective functional surface finishes to prolong their service life. Expanded use of light alloys in high performance applications requires low cost, efficient and environmentally sustainable high performance surface finishes. A recent surface finishing innovation from Cirrus Materials Science, combining several novel technologies, offers a sustainable light-alloy coating technology that reduces the cost, energy consumption, and coating thickness required to protect components. Cirrus employs a proprietary low voltage Plasma Electrolytic Oxidation (PEO) process to deposit a tightly bonded protective layer to the alloy surface which operates at less than 5% of traditional PEO process power. Doping the bath with either carbon and/or nitrogen compounds which, under the influence of the arc temperatures and pressures introduce carbides and/or nitrides directly into the developing surface. The process creates protective functional surfaces which may include high hardness (>875 HV), superhydrophilicity (